Collapsible bag

ABSTRACT

The invention provides a collapsible bag comprising a prismatic, tubular body having hingedly connected wall panels so as to be collapsible to flat condition, and hinged flaps at the ends of the tube to constitute the bottom and the top of the bag, all parts being kept in interlocking relationship by means of a carrying strap introduced between the top flaps and the bottom flaps.

I United States Patent 1111 [72] Inventors Svend Fischlein [50] Field ofSearch 1. 229/37, 52, Albertslund; 54, 53; 150/17, 32, 33, 42, 52;224/5, 26 Peter Karpf, Borkerod; Jan K. Tragaardh, Lyngby, a" f Denmark[56] References Cited [21] Appl. No. 831,677 UNITED STATES PATENTS 1Filed Julne 9, 1969 501,053 7/1393 Burke 229/54 (45] Patented June 29,1971 3,024,959 3/1962 Kuchenbecker 229/17 G Assignee Svend AageFischlein 3,117,710 1/1964 Beach, Jr 229/17 0 clberssllln 3 42} dh3,361,333 1/1968 Stuart 229/17 G ysai arp an sai ragaar [32] PriorityJune 7, 1968,3111]. 9, 1969 FOREIGN PATENTS [33] Denmark 590,024 3/1959Italy 54/ [31] 2,657 and 114 Primary Examiner-David M. BockenekAtt0rney-lmirie and Smiley ABSTRACT: The invention provides acollapsible bag coms prising a prismatic, tubular body having hingedlyconnected g wall panels so as to be collapsible to flat condition, andhinged [52] US. Cl 229/54, flaps at the ends of the tube to constitutethe bottom and the 229/52, 229 /53 top of the bag, all parts being keptin interlocking relationship [51] Int. Cl B65d31/16, by means of acarrying strap introduced between the top flaps B65d 33/06 and thebottom flaps.

PATENTEnJunzslen 3,589,594

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COLLAPSIBLE BAG This invention relates to collapsible bags provided witha carrying strap which may be used as shoulder strap, for example.

Collapsible bags known heretofore are generally made of soft tissuewhich may be rolled or folded up, and are permanently connected with acarrying handle or strap. Such bags offer little protection to theobjects contained therein. Bags having stiff walls so as to be capableof protecting their contents against shocks and external pressure, arenot collapsible.

Collapsible packaging containers made of corrugated paper board, or thelike, and having stiff walls and bottom, are known, but such containersare not suited for use as handbags, i.e. because they have no carryinghandle or strap. Furthermore, once such containers are folded up, thebottom thereof, at least, must be permanently secured in its operativeposition in order to be able to carry the load of the goods packedin thecontainer, so that the latter is no more collapsible.

Accordingly, it is an object of the present invention to provide a baghaving stiff walls and a carrying strap, but being nevertheless easilycollapsible when not in use.

Another object is to provide a collapsible bag having hingedly connectedstiff panels for constituting the walls, the bottom and the lid thereof,and a strap for carrying the bag and locking the bottom of the bagagainst bursting open under the action of the weight of the objectcontained in the bag.

A further object is to provide a collapsible bag of the kind describedhaving a separate carrying strap which becomes operatively connectedwith the body of the bag when the flaps or panels constituting thebottom and the lid of the bag are folded in to close the ends of thetubular body of the bag.

Still another object is to provide a collapsible bag with stiff wallsand bottom which is simple in construction and inexpensive to make.

Other objects and advantages will appear as this specification proceeds,reference being now had to the drawings, in which:

FIG. 1 illustrates a portion of a foldable blank for the bag of thisinvention,

FIG. 2 is as top perspective view of the bag made from the blank of FIG.1 and provided with a strap,

FIG. 3 is a bottom perspective view of the same,

FIG. 4 illustrates a modified form of the blank shown in FIG. 1, and

FIG. 5 is. an end view of the bag made from the blank of FIG. 4.

The blank shown in FIG. 1 may be made of any suitable, stiff sheetmaterial which is made pliable at the folding lines discussedhereinafter. Such materials are, for example, leather, plastic sheets,paper board or like fibre material, especially if coated with tissue. Inthe latter case, the various panels defined between the folding lines ofthe blank may be made separately and be hingedly connected with eachother along the folding lines by means of the tissue coating.

The blank shown in FIG. 1 is first folded along parallel folding lines3, 2 and 4 to constitute a prismatic tube having rectangular wall panels31, 32, 31a and 32a, the tube being closed along the edge 1, e.g.through heat sealing in case of a blank of heat-sealable material. Theedge 1 will then constitute a folding line of the tube. When collapsedto flat condition, the tube comprises two equal portions defined betweenthe folding lines 1 and 2 lying flat upon each other. Near each end, thetube is provided with transverse folding lines 5, 6, 7, 8 and 9, 10, 11,12, respectively defining flaps or panels 33, 34, 33a, 34a and 35, 36,35a, 36a, respectively, for folding in to constitute a closure at eachend of the tubular body of the bag.

The flap or panel 33 defined between the folding lines l, 3 and 5 (FIG.1, upper left) is formed with a pair of additional folding lines 13 and14 starting at the point of intersection between the folding lines 1, 5and 3, 5, respectively, and extending under an angle of 45 with thesefolding lines. The flap 33 is formed with a recess 21, the lateral edgesof which meet the inclined folding lines 13 and 14 at points spaced adistance which is slightly greater than the width of the carrying strapdescribed hereinafter. Subject to this condition, the recess 21 maybeformed in any desired manner. In the example illustrated, the recess 21is shown as being trapezoid. Generally speaking, the area definedbetween the inclined folding lines 13 and 14 should have a width atright angles to the folding line 5 which is smaller than half the lengthof the flap along the folding line 5, so that the folding lines 13 and14 do not intersect each other.

Similar folding lines 15, l6; 17, I8; and 19, 20, respectively, andrecesses 22, 23 and 24, respectively, are formed in the flaps or panels33a, 35 and 35a defined between the folding lines 2, 7, 4; 1, 9, 3 and2, 11, 4, respectively.

When the flat, collapsed tube is to be used as a bag, it is folded torectangular section, and the flaps 34, 34a and 36, 36a are folded in toconstitute the lid and the bottom respectively, of the bag, as shown inFIGS. 2 and 3, while the flaps 33, 33a and 35, 35a remain in aprojecting position. When folded along the inclined folding lines 13-20,these flaps constitute closed channels or guideways through which acarrying strap 25 is threaded. This strap may take the form of anendless belt or loop, or it may be provided with a buckle or clasp (notshown) for adjusting the length of the strap. The strap may be placed inthe body of the bag before or after fold ing in of the top and bottomflaps 34, 34a and 36, 36a as desired, but in any case it should becaused to extend through the channels or guideways formed by the flaps33, 33a and 35, 35a and along the inside of the wall panels 31 and 31aEvidently, a portion ofthe strap 25 will extend from one end of thebottom 36, 36a of the bag to the other (FIG. 3), and when the strap ispulled away from the top side of the bag, the channels or guidewaysformed by the flaps 35 and 35a are bent in towards the outside of thebottom panels 36 and 36a. Now, when the objects to be carried in the bagare introduced therein, after the top panels 34 and 34a have beenflipped open, the weight of the objects is transmitted through thebottom panels 36 and 36a to the flaps 35 and 35a and the strap 25. Thus,the bottom of the bag remains closed, while the to thereof is easy toopen.

Obviously, the strap 25 may be pulled in the opposite direction relativeto the body of the bag, so that the flaps 34, 34a constitute the bottomand the flaps 36, 36a constitute the top of the bag.

The blank shown in FIG. 4 in which like reference numerals denote likeparts, differs from that shown in FIG. '1 in that slots 27, 28, 29 and30 are provided along part of the foldinglines 5,7, 9 and 11,respectively, through which slots the strap 25 may pass from the insideof the flaps 33, 35 and 33a, 35a to the outside of the wall panels 31and 31a, respectively, as shown in FIG. 5. This measure will assist inkeeping the carrying strap 25 positioned when the top of the bag isopen.

It will be appreciated that, when the bag is carried in the strap 25,all parts are interlocked so as to insure complete stability of the bag.However, as soon as the tension of the strap 25 is relaxed, e.g. whenplacing the bag upon a table, the top of the bag may be readily openedby lifting the flaps 34, 34a, or the bag may be taken completely apartand collapsed to flat condition. Y

The width of the top and bottom flaps 34, 34a and 36, 36a at rightangles to their respective folding lines 6, 8, 10, 12 should be greaterthan half the width of the wall panels 31, 31a, and smaller than thiswidth, so as to insure a suitable overlapping, as shown in FIG. 2.

Referring to FIGS. 1 and 4, it will be observed that the lateral marginsof the lid flaps 34, 34a and bottom flaps 36, 360 are coincident orcoextensive with the lateral hinge margins 2-4. Additionally, the endwalls 31, 31a have hingedly connected to the upper margins 5, 7 andbottom margins 9, 11 a series of polygonal segments convenientlydescribed as sleeve-forming channels which are clearly illustrated inFIGS.

2 and 3 at 330, for example. These channels are formed when the cover orlid panels 34, 34a and 36, 360 are in juxtaposed relation as is clearlyevident from FIG. 2.

The sleeve-forming channels comprise a pair of isosceles triangularsegments hingedly connected to the lateral margins of the rectangularlid flaps, see FIGS. 1 and 4, and include lower hinge margins at l320,each respectively comprising opposite sides of a trapezoidal segment 33,33a, and 35, 350, respectively. These trapezoidal segments have theirlonger base 5, 7, 9, and 11, respectively, hingedly connected at theupper or lower ends of the end walls 31, 31a.

We claim:

1. A foldable-flat bag comprising a cubical, tubular body includingalternate pairs of side and end wall panels hingedly connected atlateral edges for forming a tubular body when erected:

rectangular lid and bottom closure flaps hingedly connected torespective upper and lower marginal edges of said sidewall panels foroverlapping each other at their free edges when the bag is erected andthe lid or bottom is closed;

said closure flaps having lateral hinge margins coincident with thelateral marginal edges of said sidewall panels therebeneath;

sleeve-forming channels comprising segments hingedly connected torespective upper and lower marginal edges of said end wall panels;

said sleeve-forming channels comprising pairs of segments hingedlyconnected at one edge to the lateral hinge margins of said rectangularlid and bottom closure flaps;

said pairs of segments converging at hinge lines bordering anintermediate segment hinged to the respective upper and lower edges ofsaid end wall panels;

said segments forming a flat, open-ended channel when juxtaposed andsaid lid or bottom closure flaps are in a closed position; and

a strap threaded through said open-ended channels between saidjuxtaposed segments.

2. The structure as claimed in claim 1, in which said pairs of segmentsare triangular and said intermediate segment is trapezoidal.

3. The structure as claimed in claim ll, wherein said strap is threadedwithin said bag and along the inner surface of said end walls, and saidstrap extending through said channels flanking the bottom closure flapand being disposed exteriorly and juxtaposed beneath said bottom closureflaps.

4. The structure as claimed in claim 1, in which the end wall panelsinclude a slot intermediate of the upper and lower marginal edges, saidstrap being threaded through said slots.

5. The structure as claimed in claim 4, in which said strap extendsvertically on the outer surface on said end walls.

1. A foldable-flat bag comprising a cubical, tubular body includingalternate pairs of side and end wall panels hingedly connected atlateral edges for forming a tubular body when erected: rectangular lidand bottom closure flaps hingedly connected to respective upper andlower marginal edges of said sidewall panels for overlapping each otherat their free edges when the bag is erected and the lid or bottom isclosed; said closure flaps having lateral hinge margins coincident withthe lateral marginal edges of said sidewall panels therebeneath;sleeve-forming channels comprising segments hingedly connected torespective upper and lower marginal edges of said end wall panels; saidsleeve-forming channels comprising pairs of segments hingedly connectedat one edge to the lateral hinge margins of said rectangular lid andbottom closure flaps; said pairs of segments converging at hinge linesbordering an intermediate segment hinged to the respective upper andlower edges of said end wall panels; said segments forming a flat,open-ended channel when juxtaposed and said lid or bottom closure flapsare in a closed position; and a strap threaded through said open-endedchannels between said juxtaposed segments.
 2. The structure as claimedin claim 1, in which said pairs of segments are triangular and saidintermediate segment is trapezoidal.
 3. The structure as claimed inclaim 1, wherein said strap is threaded within said bag and along theinner surface of said end walls, and said strap extending through saidchannels flanking the bottom closure flap and being disposed exteriorlyand juxtaposed beneath said bottom closure flaps.
 4. The structure asclaimed in claim 1, in which the end wall panels include a slotintermediate of the upper and lower maRginal edges, said strap beingthreaded through said slots.
 5. The structure as claimed in claim 4, inwhich said strap extends vertically on the outer surface on said endwalls.